Heat Stroke in Pets


Heat Stroke

You’ve seen it, the pet locked in a parked car on a warm day. Maybe you’ve even done it yourself? What you may not know though, is that such a situation can quickly lead to severe, expensive, and often fatal, problems for such a pet.

You see, when a pet’s body temperature rises and stays above 104oF for even a short period of time a myriad of problems can ensue. Without going too much into the physiology and biochemistry behind it, at such temperatures the enzymes and the vital metabolic reactions they are involved in cease to operate properly – and the result is dysfunction of multiple different body systems. This dysfunction may manifest as collapse, lethargy, vomiting, diarrhea, abnormal bleeding, kidney failure, liver failure, seizures, and even death. There’s good news though… Heat Stroke is typically a completely (and easily) preventable emergency.

What’s that you say? You only leave you pet in the car for 15-20 minutes to run into the store. Oh, and you leave the windows ‘cracked’ too. Well, then your pet is safe, right? Perhaps (and likely) not.


  • A trip into the store that is planned to take even 5-10 minutes can in fact take much longer. Ever bump into a chatty neighbor while on such an errand? Ever choose the wrong check-out line and get stuck with the slowest cashier on record? The fact is, the actual duration of any trip into a store is only partially within your control. And those factors outside of your control may lead to an expensive and very uncomfortable wait for your pets – and one that can prove fatal too.
  • On a warm day, in the right conditions, even 15-20 minutes of enclosure in a hot car can be enough to bring on a case of Heat Stroke in your pets. And this is particularly true in pets of certain breeds and those with certain pre-existing medical conditions. (See study and further information below.)
  • While ‘cracking’ the windows does have some effect on slowing down the temperature rise inside a car, that effect is minimal and it’s not enough to prevent the temperature from rising to fatal levels.

A study published by the Geosciences Department of San Francisco State University in 2003 (http://ggweather.com/heat/heat%20study.pdf) showed clearly how quickly the temperature inside a parked car can rise to dangerous, and even fatal levels. What’s even more concerning is that it can happen in temperatures far lower than what most people are likely to think would be dangerous, and that leaving the windows ‘cracked’ has very little effect on preventing it. For those of you short on time, or patience for reading such studies, here are some of the more salient points…


  • On one 72oF day the temp inside the enclosed car reached 93oF in 10 minutes, 105oF in 20 minutes, 110oF in 30 minutes, and 119oF in 60 minutes.
  • The average temperature rise over the 16 days they conducted the study was 19oF by 10 minutes29oF in 20 min33oF in 30 min, and 43oF in 60 min.
  • Multiple studies have shown that leaving the windows ‘cracked’ has only a minimal, and overall insignificant protective benefit. One such study showed that the average temperature rise of 3.4oF per 5 minutes in an enclosed car was only decreased to 3.1oF per 5 minutes by ‘cracking’ the windows. This equated to a difference of only 3.6oF over the 60-minute study period (40.8oF total heat rise with windows fully closed, compared to 37.2oF rise with windows ‘cracked’). Another study showed only a 2oF difference at the end of the 90-minute study period between a fully enclosed vehicle and one with the windows ‘cracked’.

Ok, I’ve (hopefully) convinced you not to leave your pets in parked cars. But did you know that Heat Stroke happens in other common scenarios too? It happens to pets left in the open beds of pick-up trucks without protection from the sun, it happens to pets left outside on hot days without adequate shelter and drinking water, and it (frequently) happens to pets who over-exert themselves on warm, humid, or hot days.

As mentioned above, certain breeds of dogs and cats, as well as those with certain pre-existing medical conditions are at increased risk for suffering Heat Stroke and other heat-related illness.


  • Brachycephalic, or ‘snub-nosed’ dogs, such as Bulldogs (English and French), Boxers, Pekingese, Shih tzus, and others (including mixes of these breeds) are very much at increased risk. As are the brachycephalic cat breeds, such as Persians and Himalayans.
  • Because of their decreased ability to regulate their own body temperature, very young and very old pets are also at increased risk of developing Heat Stroke.
  • Pets that are obese (be honest with yourself) or have arthritis (or other painful orthopedic conditions) are similarly more likely to develop Heat Stroke in lower environmental temperatures and more quickly because of their increased workload and the increased heat generation that it engenders.
  • Pets with heart disease or certain respiratory diseases, such as laryngeal paralysis, collapsing trachea, and brachycephalic obstructive airway syndrome, are at grave risk of developing this condition. And when they do, it is more likely to prove fatal because of their underlying condition.
  • Pets that have previously had a bout of heat-related illness are at increased risk for another bout.
  • Lastly, although a rare condition, Myesthenia Gravis, a disorder of a pet’s neuromuscular system, also significantly increases a pet’s risk for the development of Heat Stroke.

Do any of your pets match these descriptions? Maybe they exhibit several of these criteria? If so, you should really be paying attention to this post. And if you know anyone with pets that fit any of these descriptions, you should do them a favor and share this or send them the link to this post. You may just save their pet’s life. And you’ll definitely save them an awful lot of time, heartbreak, and money too.

If you are “fully on-board” with the importance of preventing heat stroke you can stop reading here. If you still need some convincing, please read on…

Ok, so perhaps the risk of your pet’s severe discomfort, debilitation, and death aren’t enough to convince you to do all that you can to prevent this condition. (There may be some of you out there.) Well, hopefully the financial costs that are typically associated with the treatment of this condition will.

If your pet develops Heat Stroke, which by definition means that there is involvement of their central nervous system, you are likely to be faced with a hospitalization and treatment bill that extends well into the $3,000-5,000+ range. Some of these pets need to be put into a medically-induced coma or have other intensive treatments to halt any seizures that may occur. If they also have evidence of bleeding abnormalities, such as small bruises on their skin or gums, or blood in their diarrhea, the treatment costs can run significantly higher, as these pets require blood plasma transfusions in an attempt to restore their normal clotting function.

Hopefully now everyone is convinced?

Ok, so perhaps there may still be some out there who are (somehow) not convinced of the benefits of doing what they can to prevent Heat Stroke in their pets? (Hopefully not, but it is possible.) If you are one of them, then I have this to say to you… (1) you have no compassion, (2) you shouldn’t have pets, (3) you have more money than sense, and (4) you should know that in some states and counties it is actually illegal to leave a pet in an enclosed vehicle, or other space, that poses a danger to a pet’s wellbeing. Meaning you can not only face stiff financial penalties, but, in some cases, potential jail time as well. Don’t believe me? Check out this information from Michigan State University College of Law: http://www.animallaw.info/articles/qvuspetsincars.htm. And even if a particular state doesn’t have such a law on its books (yet), your city or municipality may. Hopefully I have now convinced everybody – yes?

Do you know someone that doesn’t think twice about leaving their pet in the car on a hot day while they run errands? Please do share this with them. Hopefully it will give them pause and encourage them to give such actions a second thought.

Now that everybody knows what Heat Stroke is and why you should do all that you can to prevent it, let’s cover the how. Like I mentioned at the outset of this post, the prevention of Heat Stroke is so often easily achieved. Follow the advice below to keep your pets out of the ER and your money in your wallet, and pass it along to help your friends and family do the same.

Preventive Measures:


  • On any day that the outside temperatures are expected to go above 60oF, do not take your pets with you for a day of running errands around town – leave them at home instead, in a well cooled and ventilated space. Don’t kid yourself and use the excuse that they hate being away from you – if they get Heat Stroke, they will have to be away from you. Either for a multiple day stay for treatment in a veterinary ICU, or in an urn or coffin after they have died as a result of Heat Stroke that could have been so easily prevented. A few hours at home alone doesn’t sound so bad now, does it? Think about it.
  • For dogs that live predominantly outdoors, especially on any day that will have temperatures above 60oF, be sure that they have easy access to effective and reliable shelter from the sun and plenty of fresh water to drink. On particularly hot days its a good idea to leave them with a kiddie pool filled partially with water that they can climb in to cool off. And you should also leave an additional water bowl outside for them that has been frozen overnight; this way, as the temperatures rise and the ice melts, they will have a replenished source of cool water to drink.
  • Take preventive measures when taking your pets on road trips during the warm and hot months of the year. These include taking along plenty of fresh water for them to drink (and a bowl for them to drink it from too) and not leaving them in the car while you go in to have a meal at a road-side restaurant (pack a picnic lunch, or get take out, instead and eat outside with them at a rest-stop or park, preferably in the shade). On particularly hot days, run the air-conditioning (if your car is so equipped) rather than driving with the windows open. If you do drive with the windows open though, be sure that your pets are properly restrained, as this will prevent them from jumping out the open window. Pets that jump out open car windows, even if that car is parked, are frequently injured (sometimes with lifelong injuries, and sometimes fatally so) and also have the potential to cause an accident, which can result in human fatalities too.
  • Take preventive measures when flying with your pets, and always be sure to check your particular airline’s regulations for doing so. Good preventive measures include booking non-stop flights whenever possible, traveling in the early morning or late evening when temperatures will be cooler, and never flying with brachycephalic dog or cat breeds (see special note about these breeds above).
  • On warm and hot days avoid exercising your dogs in the middle of the day. Do all of their walks, hikes, ball chasing, and other exercise in the early morning and late evening when the temperatures are cooler. Make sure that your dog walker is aware of this condition, and adheres to these recommendations as well.
  • For dogs that are particularly prone to this condition, and with all dogs early in the summer and spring when they may not be acclimated to the heat, consider using one of the cooling vests for exercise during the warmer parts of the day (but still allow them to rest frequently and provide ample fresh water for them to drink, and still never leave them in an enclosed vehicle). Two good examples of these vests are the Ruff Wear Swamp Cooler Vest and the RCPM Cool Vest by Glacier Tek.
  • Avoid or correct obesity in your pets. Allowing your pets to achieve an appropriate body weight and condition can greatly help to decrease the energy the have to exert for even the mildest exercise, and therefore have a significant impact on the prevention of Heat Stroke (and a host of other medical conditions and emergencies). Speak with your veterinarian about your pet’s weight and an appropriate and safe weight loss plan. See my blog post on this important subject by clicking here.
  • Work with your veterinarian, and any appropriate veterinary specialists, to achieve control and management of your pet’s chronic medical conditions. As highlighted above, certain conditions will predispose your pet to the development of Heat Stroke. Be cognizant of this and work with your veterinarian to achieve whatever level of control is within your means and to educate yourself on your pet’s condition(s). This includes appropriate pain management for your pet’s arthritis.
  • Lastly (for now), if you see a pet locked in a parked car on a warm day – call 911! As you hopefully now appreciate, this is a true emergency that can rapidly progress to that pet’s death – even if the windows are ‘cracked’ or the sunroof is open. Check out this great segment on this very subject from the ABC News program What Would You Do – now you know the answer, and more importantly… you know why.

You are now well ‘armed’ to prevent Heat Stroke from affecting your pets. But if one ‘slips through’ and you suspect heat-related illness in your pet, take them immediately for veterinary evaluation and treatment. If there will be a significant delay in obtaining treatment – such as you are hiking out in the ‘middle of nowhere’ or you don’t have a car – you can follow the ‘first aid’ steps below to help your pet. Of course, these steps are just initial measures and they should always be followed-up with a visit to a veterinarian for evaluation and possible continued treatment.


  • Move your pet into the shade or an air-conditioned environment to prevent further heat absorption.
  • Measure their rectal temperature with a digital thermometer (not glass) and plenty of lube (Vaseline, KY, or similar). If their temperature is above 104oF, begin cooling them by spraying cool (not cold) water over their body. If you have a fan handy, you can turn it on and have it blow over them. This can help to establish evaporative cooling. It is important though to cool them slowly and not too low. You should track their rectal temperature frequently (every minute or so) and stop actively cooling them when their rectal temperature reaches 103.5oF. Under no circumstances should you put your pet in a tub of ice cold water! This will lead to constriction of the blood vessels under their skin and actually impair their ability to get rid of their excessive body heat.
  • Once you are done cooling them, dry them off slightly with a towel – this can help to prevent excessive cooling from occurring.
  • You can offer your pet some water to drink. But you shouldn’t let them drink too much or too fast, and you should never attempt to force water down the throat of a pet that is too mentally obtunded to drink on their own.
  • Again, even if you have done these ‘first aid’ measures, your pet should be brought for veterinary evaluation as soon as possible. Problems can still exist or develop, and your veterinarian is trained to detect, anticipate, and treat them.

source: http://www.thepreventivevet.com/_blog/The_Preventive_Vet/post/Heat_Stroke_in_Pets/